SR2 starter replacement

[KC7NOA]

I see how your saposed to pull this apart ...

Yep, some idiot put this on backwards ...

[mikenash]

As said, someone has put the pulley and taper-clock assembly on backwards

Obviously you can't get into the back to swap grub-screws from "tightening" to "loosening" holes.  But whoever put it on wouldn't have been able to tighten the two taper halves against each other, either - as he couldn't get at the grub-screws

So, probably, it has been slid/tapped/hammered onto the shaft and is now retained in place by the grub-screw which is on top of the keyway?  Possibly also another grub-screw at 90 degrees to that?  That would be common practise.  I would think getting that/them out may allow you to use a puller and get the pulley off the shaft

If it will move at all, and if you have access to a three-jaw puller - perhaps consider tapping it further along the shaft a millimeter or two so that you can clean the shaft properly before pulling it off

Good luck

[cobbadog]

Good explanation Mike and suggestion as to how to get it apart. The best thing to get right first is the removal of the rust from the shaft.

[KC7NOA]

Iv bought some metric and sae Allen wrenches and 1/8th slips and 9/64 does not fit ....

What am I looking for?

[KC7NOA]

There is only one scrub screw ... what is 180 deg from the scrub screw is a split in the ring ...

[broncodriver99]

There usually is only one on a taper lock. It should be right above the key. That may be a metric hub. None of the metric allens fit?

[KC7NOA]

There usually is only one on a taper lock. It should be right above the key. That may be a metric hub. None of the metric allens fit?

No ... the 2 was small and the 2.5 too big

[cobbadog]

If neither the Imperial or Metric keys fit then that grub screw is stripped from past users using the wrong size key.
The next thing to do is to drill it out. Drill it to being just under the size hole if you can see it or start guessing the size, drill it and try using a puller. If no go use the next size up drill bit. Once off and if you have damaged the thread re tap it the next size up and buy a new grub screw to suit.

[mikenash]

Just a comment on the above advice about 'drilling it out" . . .

While that is the last resort, of course, it may be worth mentioning that grub screws are hard - I have found they will resist drilling quite strenuously.  I guess if it was heated until it glowed and then allowed to cool it might be de-tempered

If it really cannot be removed, what I would try next is:

Heat it up with butane or a gas-plant until it glows, then leave it to cool

spray INOX or your lube of choice all over it repeatedly so it has the best chance to sink in (heating the grub screw will have "burnt" some of the material between the screw and the body and a penetrant should now soak in better)

Find the allen key (metric or imperial) that is just slightly too large and cut a straight section off the arm of it with a nice square end

Using a small cutting disc on the angle grinder, cut a shallow groove in each of the six faces of the hex key/allen key

Use something small and pointed plus compressed air to clean out the hex on the top of the grub screw thoroughly

Then HAMMER your modified/butchered hex key/allen key into the top of the grub screw.  It needs to be TIGHT

The put a big spanner or vice grips on the shaft of that allen key and twist

If that doesn't work - I guess drilling is next.  You may like to research "left-handed drill bits"

Good luck

[cobbadog]

Hi Mike, good advise but I have found a number of grub screws that are not as hard as they should be and using brand new quality allen keys in a grub screw that has never been remove from new and had them chew out. They have been soft and of Chinesium origin. So the replacements have been Australian made grub screws that are hard as you rightly posted.
If the OP's grub screw is already rounded out or stripped then it too must be soft so a drilling maybe the only option after trying to jamb a slightly oversized allen key in with a hammer.

[mobile_bob]

if you have to drill them out...

don't bring them to red hot, the relatively cooler surrounding metal will chill them and make them even harder than they started out to be.

if you can... sand off the paint or rust around the area where the set screw goes in, and then heat the area to a dark blue, make the area about an inch around if possible, all blue if possible and slowly let it cool by bringing the flame back a bit at a time over about a minute or so... then go get a cup of coffee or a beer (pick your poison)... wait until it is cool enough to handle.

then the little buggers will drill right out without much problem

also i cool my drill bits with water, i use a standard plastic pop bottle with an eighth inch hole drilled it in to dribble water and keep the bit cool.

never had one that couldn't be drilled out, if you anneal them properly first.

fwiw
bob g

[KC7NOA]

I think it's slowly moving .... I dont want to put alot of pressure on it

[cobbadog]

Yes, there seems to be a small gap there now. Keep up the good work in being patient. You will win.

[KC7NOA]

Weell... it broke along the keyway ... need to replace the pulley...

How do I order an exact replacement?

[cobbadog]

With these old engines most parts canot be b ought off the shelf. Not sure where in the world you are but you will now need to find a dealer in Lister parts or hope that a reader has a spare pulley. Put up a pic of what the pulley looks like now, it may be able to be repaired. Look online at the usual auction sites as well.